Brake shoe key



Jam 28, W36. c. R. BUSCH BRAKE SH'OE KEY Filed July 14, 1951 2 Sheets-Sheet 1 INVENTOR ATTORNEY C. R. BUSCH BRAKE 'snos KEY Filed July 14, 1951 Jan 28 193%.

2 Sheets-Sheet 2 Patented Jan. 28, 1936 'rrso STATES PATENT OFFICE BRAKE SHOE KEY Charles R. Busch, Orange, N. J., assignor to Buffalo Brake Beam Company, New York, N. Y., a corporation of New York Application July 14, 1931 Serial No. 550,661 26 Claims. (01. 188243) The present invention relates to more or less a preferred and a modified construction, and radical inprovements in brake shoe keys of the wherein type wherein a substantially solid lug extends Figure 1 is a side elevation, parts broken away rearwardly of the upper end of the key, away and in section, of a brake shoe and its head held from the face of the brake shoe retained by the in place by the improved key when driven into 5 key upon the corresponding brake shoe head. the key-Way; Whiie preferably the improved key has a lug of Fig. 2 is a similar view showing the key only a solid type, the invention is not necessarily repartly driven into the key-way;

stricted thereto. The improvements also include Fig. 3 is also a similar view showing the key 0 certain incidental improvements in the brake driven in for a less distance than in Fig. 2; shoe head. Fig. 4 is a side elevation of a preferred con- With the usual type of brake shoe key, it has struction of ,brake shoe key; been found in practice that a given key cannot Fig. 5 is an elevation, taken at right angles to take care of varying conditions in the key-way of Fig. 4; I the castings through which the key passes, nor Fig. 6 is a side elevation of another construction compensate for varying conditions due to wear of key; and between the brake shoe and head, caused by ac- F g- 7 is an e evat on at r t a e he etotion of the brakes and vibration between the The improved key is preferably composed of locked parts. Therefore an important object of two suitable lengths of strip steel which are bent the present invention is to provide a non-vibratand preferably connected before the same are 20 mg and a self-locking key for brake shoes. tempered, after which the steel is tempered so as Another object of the invention is to provide a to provide a pair of legs H], II composed of fiat key which may be driven into place in the usual or leaf springs, as shown in Figs. 4 and 5, almanner from its upper end and be withdrawn in th ugh t e strips may fi be o n c ed befO e the usual manner, the key being preferably of a n if found s A more 1' less flattened 25 length to extend clear through the key-way prolug 52 xt n s f m the k y war ly of e vided therefor, but which key is provided with brake shoe held by the key. egs I I being a pair of legs preferably which are bowed for broad and preferably of substantially fiat leaf substantially their entire length and which legs sp ng m tal ace each other, and are bowed have considerable springiness and resiliency aw y from eac O e a show clearly in Fig. 4. 3 throughout the entire length of the legs, so as to y hu b w t legs o a y om each compensate for varying conditions in different Other n the p a y mutually 111 3, a 0 key-ways and to take up wear of the locked parts. siderable p e ap is p o c d between the Another object of the present invention is to l g f t entire length of the ya e t provide a key w th pair of oppgsed spring legs, of steel is in eiTect a steel bar and the key com- 5 one of which has a bearing portion which is deprises such a be flected in a direction towards the brake shoe As shown in Figs- 4 and t outwardly bowed when the key is in place, so that the bowed spring leg i l is Provided With a intermediate Portion legs will act in opposite directions to retain the i3 Which is deflected w frOm the Other le 0 40 brake shoe on its h ad without vibration. and xt s l tudinal y of t e H r m r 40 Other objects of the present invention are to than a third of the length o he Outer provide one of the spring legs of the key th stu'face of the deflected portion 13 of the leg I i shoulders, so located that the key is prevented forms an extended bearing Surface, which has from jumping out of place whether the same is a curve appr0Xima t ing the general curve of t driven into the key-way for its entire length or leg h .provlsion of the extended bearing for distances less than such length, so that the portlon a3 momenta-1y produces on the Outer surimproved key has a wide range of adaptability to face leg i an abrupt shoulder M at the upper varying conditions between different brake shoes i g gg g g iggi i $2 5 g ggf z andfihehrispecfive heads' L shoulder I4 is located much nearer the lug I2 5 Tnege bemg amsng the obJec'rs of the present than is the shoulder I5. When the leg H is coml' v h same Consists 9 Certain features posed of substantially fiat spring metal, the shoulof construction and combinations of parts to be d r l4, l5 extend transversely of the leg II and hereinafter described and then claimed with refare substantially parallel with each other. Be- 5 erence to the accompanying drawings, illustrating tween the shoulder l5 and the free end of the in many cases.

2 leg ii, the leg is formed with an outward corrugaticn or rib 16 which extends transversely and is substantially parallel with the shoulders before mentioned, constituting an additional abrupt shouider located adjacent the free end of the leg ii. The shoulder 16 is also deflected away from the other leg It, so that all of the shoulders l4, l5 and i6 extend toward the brake shoe when the key is in position.

The terminal or free end ill of the leg It preferably extends a distance beyond the terminal of the other leg I i, which latter terminal has a bearing relation with the leg ii]. The extended free end it of the leg iii is provided to facilitate the introduction or the key into the key-way and to constitute a leader for directing the lower end of the key through the key-way as the key is being driven into place. The extended terminal of leg it is preferably slightly deflected in a direction away from leg H to avoid its possibly catching inthe' key=way when the key is being driven in. Preferably both of the terminals of the legs H], ii are also tapered as shown.

Again referring to Fig. 4, the lug i2 is formed by bending the upper ends of the legs IE], I I, similarly, so as to provide rearward tongues lips is, is, which are matched together and united as by rivets Iiia. The uniting oi the legs may also be done by Welding or the like.

Referring now to Fig 1, the improved key is shown as driven for almost its full length, except for the projecting lug l2, into the key-way between the brake-shoe head 20 and the brake-shoe.

2!. A full inward drive of the key is permitted It will be seen that the brakeshoe head is provided with a pair of members 22, 23 which are spaced apart and extendv outwardly from the face of the brake-shoe head. A complementary projecting member 2a is provided on the back of the brake-shoe and fits into the space between the two projecting members 22, 23. Registering apertures 25 extend through the projecting members 22, 23 and 24, and constitute portions'of the length of the key-way. Through these apertures thelegs 18, l! of the key-are driven, with the result that the deflected portion 53 or the key bears upon corresponding walls of the projecting members 22, 23 while the leg Hi bears upon the corresponding wall of the projecting member 24 or the brake-shoe. Inasmuch as the inward driving of the key causes the resilient legs In, to yield, the leg H is flexed and bowed in opposite direction from its original set, thereby firmly pressing the leg Ill against the adjacent surface of the projecting member 23.

The threading oi the key into the key=way will cause the shoulder 15 to further tend to flex both of the legs l0, H and to put them under greater tension, which tension is maintained by the extended bearing portion l3 of leg H. When the key is thus in place, the shoulder Hi will be located between the projecting member 22 on the head 2E! and. a cross-piece 26 in the upper toe of the head 20, through which a part 28 of the keyway is formed. It wiil be seen that any considerable upward movement of the key and the jumping thereof out of place so as to disconnect the parts, is precluded by the abutment provided by the cross-piece 26, inasmuch as the shoulder it comes in contact therewith if the key moves upwardly, and thereby the removal of the key due to vibration of the parts is precluded.

It will be observed that in whatever way the improved spring key is contemplated it preferably s has reversely bent portions which may bear in opposite directions upon the lugs '22, 23 of the.

ead and the lug 24 of the shoe.

When the key is in place as in 1, it will be seen that the shoulder it at the free end of the leg H is located between the projecting member '23 of the head 2E! and a cross-piece 27 which extends across the lower toe of the head 20, through which a portion is of the key-way passes. It will be seen that the free ends of the key are very close to the cross-piece 2i, and would tend to bear upon the same if the construction or key shown in Figs. 6 and 7 is employed, and that ii the key should move upwardly for a suitable distance due to vibration the shoulder It will be brought into abutting relation with the projecting member 23, thereby also assisting in preventing the displacement of the key, and maintaining the shoe 2| in locked relation to the head 20. It

the key when in the position shown in Fig. 1 cannot readily be removed in the usual manner by engaging a lifting member under the rearwardly projecting lug I2 oi the key, its removal can be assisted by driving upwardly upon the projecting lower end of the leg l0.

It wiil be readily seen key be driven as far in as possible, the shoulder will come into firm bearing relation with the member 21 forming part of the lower portion of the head, so that the key is completely under tension from end to end, inasmuch as it is in firm bearing relation both ends oi the head and also with the apertured lugs intermediately oi such bearing points.

In Fig. 2 it is assumed that the condition between the head 20 and brake-shoe 2| is such as to preclude the full inward driving of the key. The variations which might bring this about are so numerous that they cannot be easily illustrated. In this view it will be seen that the bearing portion l3 presses in one direction upon the adjacent surface of the projecting member 22 and that the ieg/ l0 bears in opposite direction upon the adjacent surface. or the projecting member 24. It will also be seen that the shoui- 'ders M and I6 are in abutting relation with the that should the springdeflected portion 13 of leg ii bears upon the cross-piece 26, thereby tensioning the two legs l0, H, while the shoulder It at the lower end of the leg I l is in bearing relation with the rojecting member 22 of the brake head. Also the lower end 01 the leg i0 is in bearing relation with the projecting member 24 on the brake-shoe.

Another desirable form oi key is illustrated in Figs. 6 and '7. This includes a lug 30, the details of which are similar to those of the other term of the invention, but in Figs. 6 and '7 the two opposed legs 32, 33 are both originally bowed. in the same direction, the lower terminal 01. the leg 33 bearing upon the leg 32. It will be seen that the curve of the bowed leg 32 is of less radius than the general curve or the leg 33, which condition is desirable when the legs are both bowed in the same direction, in order to take full advantage of the present improvements. In this form of the invention, the leg 33 is provided at its incurved surface with an extended longitudinal bearing portion 3 5 which is deflected in a direction away from the other leg 32. This will provide a bearing portion 34, corresponding with the similarly located bearing portion of the other form of the invention, together with shoulders 35, 36 at the ends of the bearing portion 34. Also, a shoulder 31 36 and the terminal of the leg 33. Also, the free lower end 38 of leg 32 is extended as before stated beyond the terminal of the leg 33. Hence the construction of key shown in Figs. 6 and '7 possesses in a substantially similar manner the features of the other form of the invention. In driving the modified key into position, the leg 32 is flexed to a greater extent and the leg 33 to a less extent, if at all. It will be noted that the bearing portion I 3 in the form shown in Figs. 4 and 5 and the bearing portion 34 of Figs. 6 and 7, are each deflected or upset outwardly in a direction away from the opposite leg or flexible member of the key and will have a full bearing upon the inner surfaces of the head lugs 22, 23, in the position of the key as shown in Fig. 1 and likewise upon the head lug 22 when the key is positioned as in Fig. 2. Incident to such deflection or upsetting of the said bearing portions 13 and 34 the upper end of the key is set or positioned in spaced relation to the upper part of the brake-shoe so as to clear the same in both applying the key and when it is in position. This means that there is no objectionable bearing relation or friction between the upper ends of the key and the shoe when the preferred constructions of key are employed, and hence full advantage may be had of the novel features of the entire key.

Referring to the front depression formed between the shoulders I5, IS of Figs. 4 and 5, and the similar depression formed between the shoulders 36, 31, of Figs. 6 serves two purposes. It allows one of the head lugs 22, 23 to be engaged therein in each position of the key in Figs. 2 and 3, so that a selflocking effect is established and permits one of the shoulders or upsets l6 or 31 to become effective. It also provides a distinct rear bearing portion of the length of the leaf or leg H or 33 so that when the key is fully applied as in Fig. l and compressed to the maximum of say one third or one-half of its expanded size, the directly opposite surface portion of the other leaf contacts throughout therewith and an extensive mutual bearing of the lower ends of the key is thereby provided which relieves the two leaves or legs from undue strain.

In both forms of the invention as shown the relative bowing out of the shoe engaging leg or leaf is greatest at a point approximately 0pposite the center of the depression formed by forwardly upsetting the other leg or leaf between the shoulders at each end of such depression, so that the shoe engaging leg or leaf will gradually curve along easy lines in both directions from the approximate mid-length thereof, with the result that a maximum degree of fiexibility is provided without impairing the efficiency of the other features of the key in assisting in properly holding the shoe on the brakehead.

When the key is installed in using position, the intermediate portions of its legs or leaves should compress to about one-third of its expanded size without changing the eificiency of the interme diate forward depression or upset portion of the brake-head engaging leg or leaf, this being stiffened by the shoulders at each end of such depression.

is provided between shoulder and 7, such depression To sum up some of the advantages of the flexible, non-vibrating and self-locking key described and illustrated, they may be stated as follows: The improved key will fit any head now in service, whether new or worn. It will fitinto the keyway of the brake head constructed with the narrow key-way and cross-pieces or bars across the toe lugs thereof. It will fit not only the heads just mentioned, but will fit worn heads and brakeshoes. The improved key is designed not only to fit under all conditions mentioned herein, but to compress sufiiciently to allow for a tight fit in any combination of brake-heads and brakeshoes. The improved key is intended to assure a tight fit at all times, to eliminate excess wear,

and to take up through its expansion all natural wear as is occurs. Other advantages could be enumerated, but it is believed that these will suffice.

Obviously, some of the advantages inherent in the invention as shown and described are not necessarily present in a brake shoe key having two spring legs, as a key with a single leg may have those advantages and still be within the disclosure of the invention.

It is obvious that the invention as described and illustrated is susceptible of more or less modification without departing from the scope of the appended claims.

What I claim as new is,

1. A brake-shoe key, including two legs of leafspring metal and means connecting the spring legs and holding them breadthwise one in advance of the other, one of the leaf legs having outward substantially parallel shoulders extending transversely of its breadth, and located in front of the other leg, and one of the shoulders located near the free end of such front leg while the other shoulder is located relatively near to the connecting means.

2. A brake-shoe key, including two legs of leaf-spring metal facing each other breadthwise, and means connecting the spring legs, one of the leaf legs having a longitudinally extending bearing portion of substantial length. deflected outwardly away from the plane of its breadth, and from the other leg.

3. A brake-shoe key, including two legs of leafspring metal and means connecting the spring legs, both legs curved in opposite directions substantially throughout their lengths in the plane which they mutually occupy, and one of the legs having at its outer curved side an outward shoulder located along the curve, at a point between the connecting means and the free end of such leg.

4. In combination, a brake head and a shoe having a key-way and inter-engaged apertured members, the apertures registering with one another, and a key in the key-way and passing through the apertures, and including two broad legs of spring metal relatively arranged breadthwise at different distances from the shoe, and means connecting the legs, one of the spring legs having an outward shoulder located towards the free end of such leg and beyond the apertured members.

5. In combination, a brake head and a shoe having a key-way and inter-engaged apertured members, the apertures registering with one another, an abutment member on the upper part of the head and interrupting the key-way, and a key in the key-way and passing through the apertures, and including two broad legs of spring metal relatively arranged breadthwise at different distances from the shoe, andmeans connecting the legs, one of the spring legs having outward substantially parallel shoulders extending transversely of its breadth and transversely of the head, one of the shoulders located between the abutment member and apertured members and the other shoulder downwardly beyond the apertured members.

6. In combination, a brake head and a shoe having a key-way and inter-engagedapertured members, the apertures registering with one :another, and a key in the key-way and passing through the apertures, and including two broad legs of spring metal relatively arranged breadthwise at different distances from the shoe, and means connecting the legs, one of the spring legs having a longitudinally extending bearing portion deflected outwardly away from its breadth and from the other leg and pressing on the head.

7. In combination, a brake head and a shoe having a key-way and inter-engaged apertured members, the apertures registering with one another, an abutment member on the upper part of the head and interrupting the key-way. and a key in the key-way and passing through the apertures, and including two broad legs of spring metal relatively arranged breadthwise at different distances from the shoe, and means connecting the legs, one of the spring legs having a longitudinally extending bearing portion of substantial length deflected outwardly away from. the other leg and toward the shoe, and pressing on the head, and also having an outward shoulder on said one leg located below the apertures.

8. A brake-shoe key, including two legs of leaf spring metal and means connecting the spring legs, both legs curved'in the same direction in the plane which they mutually occupy, and one of the legs having at its outer incurved side an outward shoulder located between the connecting and the free end of such leg.

9. A brake-shoe key, including two legs of leafspring metal and means connecting the spring legs, both legs curved in the same direction in the plane which they mutually occupy, and one of the legs having at its outer incurved side a lengthwise bearing portion deflected outwardly therefrom and also an outward shoulder between such bearing portion and the free end of the leg.

10. A brake-shoe key, including two legs each of leaf-spring metal and means connecting them, both legs curved in the same general direction in the plane which they mutually occupy, and the leg which is curved outwardly away from the other leg having a curve of less radius than the curve of such other leg, both legs being flexible from end to end.

11. A brake-shoe key, including two legs of 1 leaf-spring metal and means connecting them,

both legs curved in the same general direction in the plane which they mutually occupy, and the leg which is curved outwardly away from the other leg having a curve of less radius than the curve of such other leg and extending beyond a such other leg at its free end.

12. A brake-shoe key, including two legs of 7 separately formed leaf-spring metal and a flat,

rearward, lug connecting the spring legs and formed from the same metal, one of the leaf legs having an outward shoulder extending transversely of its breadth and located between the lug and the free end of such leg.

13. A brake-shoe key, including two legs of leaf spring metal, and a flat, rearward, lug connecting the spring legs and formed from the same metal,

one of the leaf legs having'outward substantially parallel shoulders extending transversely of its breadth, and one of the shoulders located near the free end of such leg while the other shoulder is located relatively near to the lug, the other leg being rearward of the shouldered leg, and the lug and shoulders functioning respectively at the back and front of the key.

14. A brake-shoe key, including two legs of leaf-spring metal, and a fiat, rearward, lug con- 19 necting the spring legs and formed from the same metal, one of the leaf legs having a longitudinally extending bearing portion deflected outwardly away from the otherleg, the lug and bearing portion functioning respectively at the back and 15 front of the key.

15. A brake-shoe key, the same being formed from leaf-spring metal, and comprising two legs which are mutually opposed broadside, and means connecting corresponding ends of the legs and go serving as means for driving or withdrawing the key, the terminal of one leg bearing upon the other leg, and the terminal of such other leg extending beyond the bearing point to form a leader.

16. A brake-shoe key, including two legs of leaf-spring metal connected at one end, the legs being held breadthwise one in advance of the other, the forward leaf leg having shoulders at its opposite surfaces providing depressions in 30 such surfaces, one of which depressions provides for a maximum compression of the rear leg and the other depressionproviding an interlocking depression at the forward surface of the front leg.

1'7. A brake-shoe key, including two legs connected at one end, one leg for engaging a brakeshoe head and the other for engaging a brake shoe for connecting them together so that the former leg may be located in front of the latter leg when the key is used, the former leg having an interlocking depression at its front surface for interlocking with a part of the head, and the latter leg being of spring metal compressible toward the former leg when the key is used.

18. A brake-shoe key, including two legs con- 5 nected at one end, one leg for engaging a brakeshoe head and the other for engaging a brakeshoe for connecting them together so that the former leg may be located in front of the latter leg when the key'is used, the former leg having an elongated depression facing towards the middle portion of the latter leg, and the latter leg being of rearwardly bowed spring metal compressible toward the former leg when the key is used. 5

19. A brake-shoe key, including two legs connected at one end, one leg for engaging a brakeshoe head and the other for engaging a brakeshoe for connecting them together so that the former leg may be located in front of the latter leg when the key is used, the former leg having a bearing portion for the free end portion of the latter leg, and which bearing portion is deflected rearwardly from the adjacent upper portion of such leg, and the latter leg being of rearwardly from end to end and having along its curved formembers, the apertures registering with one anward side a. lengthwise bearing portion deflected other, and a key including a length of spring outwardly therefrom and an outward shoulder metal substantially co-extensive with the length between such bearing portion and one end of the of the key-way and extending breadthwise oi the strip. apertures, and having an outward shoulder 22, In combination, a brake-head and a shoe formed integrally therewith and located towards having a key-way and interengaged apertured' the lower end thereof beyond the apertured memmembers, the apertures registering with one anbers for engagement with a part of the head. other, and a key including a length of spring 25. A brake-shoe key, including a strip of metal extending breadthwise between the brake spring metal of a length sufficient to pass head and shoe, the key having intermediate rethrough, and at both ends beyond, the connectversely bent portions which are respectively in ing lugs of a brake-shoe and its supporting brakebearing relation with the apertured members of head, and such strip being bent to form an the head and with the apertured member 01' the abrupt forward shoulder integral therewith, the shoe to place the key under tension, the upper shoulder projecting beyond side edges of the and lower ends of the spring key being respecstrip and located at a distance from the middle tively in bearing relation with the upper and the of the strip. lower ends of the brake head. 26. In combination, a brake-head and a shoe 23. A brake-shoe key, including a strip of having interfitting attaching lugs provided with spring metal, of a length sufiicient to pass aligned openings, and a key for securing the through, and at both ends beyond, the connectshoe snugly on the head and including a length ing lugs of a brake-shoe and its supporting brakeof spring metal of sufiicient extent to pass head and such strip having an interlocking dethrough such lugs and beyond them, and the key pression at its broad front surface for interhaving an outward shoulder formed integrally locking with a part of such a brake head, such detherewith, the upper end of the spring key being pression being formed by a deflected length of in bearing relation with the upper end of the the strip itself. brake-head and the shoulder being in bearing 24. In combination, a brake-head and a shoe relation with the lower end of the brake-head.

having a key-way and interengaged apertured CHARLES R. BUSCH. 

